I have a 2001 mustang, it has some rust a just a little. So I was thinking of getting this EW Rust Converter New formula Aerosol, now what I read isthis stops and seals the rust, is that right? Then I need to use Extreme Chassis Black Primer Aerosol. then Finish with two coast of EW Extreme Chassis Black. I need to do all three steps? One coat of primer?